1. Technical Field
The present disclosure relates to a carbon nanotube slurry and a field emission device.
2. Description of Related Art
Carbon nanotubes (CNT) are very small tube-shaped structures, and have extremely high electrical conductivity, very small diameters, and a tip-surface area near the theoretical limit. Thus, carbon nanotubes can transmit an extremely high electrical current and can be used to make a field emission device. The field emission device includes a cathode conductive layer and an electron emission layer thereon.
One method for making a field emission device based on carbon nanotubes is printing a carbon nanotube slurry on the cathode conductive layer to form the electron emission layer. However, the carbon nanotube slurry usually includes carbon nanotubes, indium tin oxide (ITO) particles, glass powder, and organic carrier. The size of the indium tin oxide particles is much smaller than the size of the glass powder, and the volume percentage of the indium tin oxide particles is much greater than the volume percentage of the glass powder. Therefore, some of the indium tin oxide particles tend to fall off from the electron emission layer under a strong electric field force and cause an abnormal luminescence. In addition, the indium tin oxide particles will weaken the adhesion between the carbon nanotubes and the glass powder. Thus, the carbon nanotubes tend to be pulled out from the electron emission layer by a strong electric field force causing the field emission device to have a short lifespan.
What is needed, therefore, is to provide a carbon nanotube slurry and a field emission device that can overcome the above-described shortcomings.